As Senate Republicans passed a tax plan that would dramatically change the U.S. tax code and mostly benefit the extremely wealthy and corporations, the lone Democrat in Montana's congressional delegation received massive attention for his criticism of the hasty way the legislation was pushed through.

Senate Republicans passed their tax plan in the early hours of Saturday on a 51-49 vote, just hours after senators got an updated version of the nearly 500-page bill with notes handwritten in the margins.

Jon Tester was one of the most vocal Democratic Senators who took to social media to decry the process. He posted a minute-long video of him holding the bill up and then slamming it down on the table to show it's size. "I want you to take a look at this, folks," Tester said. "This is your government at work."

I was just handed a 479-page tax bill a few hours before the vote. One page literally has hand scribbled policy changes on it that can’t be read. This is Washington, D.C. at its worst. Montanans deserve so much better. pic.twitter.com/q6lTpXoXS0

"I can read one word. ... Can you tell me what that word is? If you can, you got better eyes than me. This is unbelievable. We're doing massive tax reform on an absolute incredible timeline. This is going to affect everybody in this country. It's going to shift money from middle-class families to the rich. It's amazing, we've been given this 20 minutes ago, 25 minutes ago. We're supposed to vote on it in a couple hours."

Tester's tweet was quickly shared across the internet; by Saturday morning it had nearly 169,000 likes and 110,000 retweets.

Montana's Republican Sen. Steve Daines, who voted for the bill, sent a tweet about two hours after Tester's that directly called out Tester, calling on him to "stop the show and vote in favor" of the bill. Daines' tweet received wide criticism before it was taken down without comment.

Tester is up for re-election in 2018 in a race that is expected to be close and expensive.

No Dems expected to vote for tax bill. 1 of Dem from a swing state facing a tough re-election told me they thought McConnell intentionally made the bill so bad for Dems..that they couldn't vote yes. That was by design so GOPers could use no vote against them in '18

On Saturday, Daines sent out a press release praising the Senate's passage of the bill.

“We are one step closer to a once-in-a-generation opportunity to grow jobs and increase wages for Montana farmers, ranchers, small businesses owners and working families,” Daines said in a release. He also said he got a $100 million tax break for Montana's Main Street business.

Daines said he initially opposed the bill until GOP leaders included a 20 percent deduction on income for pass-through businesses, which are businesses that don't pay corporate taxes. That includes sole proprietorships, limited-liability companies, partnerships and small corporations taxed as partnerships, as well as start-up small businesses — the Main Street businesses he is referencing.

Lee Newspapers reached out to Daines' office, but did not receive a reply as of Saturday evening.

Montana Department of Revenue officials previously told The Billings Gazette startups would not likely benefit from the deduction, since they tend to operate at a loss for several years. The Gazette also reported 43 percent of pass-through partnerships in the state reported zero or negative income, which means the main beneficiaries will likely be larger businesses, not small retail operations.

Tester panned the bill in a statement, saying it will add $1.5 trillion to the federal debt. That figure comes from the non-partisan Congressional Budget Office report on the bill released Saturday.

“Hard-working Montanans deserve more than a bill drafted in the dark of night, that saddles our kids and grandkids with more crushing debt," Tester said. "Sadly, Washington dysfunction has hit a new low and Montana families and small businesses deserve better than this.”